Ozone Layer: A region within the stratosphere where ozone concentrations are highest, acting as a natural sunscreen for life on Earth.
Troposphere: The lowest layer of Earth's atmosphere where weather occurs and we live. It extends from the surface up to about 10 kilometers (6 miles) in altitude.
Mesosphere: The layer above the stratosphere where temperatures decrease with increasing altitude. It is known for its meteors burning up upon entry into this layer.